Thermostat with solid filler, two-valve, type TS-107-01, located in the outlet pipe of the cylinder head and connected by hoses to the coolant pump and radiator

The main thermostat valve begins to open at a coolant temperature of 78-82° C.

At a temperature of 94° C it is already completely open.

When the main valve is closed, the liquid in the engine cooling system circulates, bypassing the radiator, through the open additional thermostat valve inside the engine cooling jacket.

When the main valve is fully open, the secondary valve is closed and all fluid passes through the cooling radiator.

Thermostat operation: A - the thermostat is closed; B - thermostat open

The body heater is connected in parallel with the radiator, and the thermostat does not disconnect it from the engine.

Therefore, when warming up the engine, you should not open the air intake damper and turn on the heater motor.

The thermostat automatically maintains the required temperature of the coolant in the engine by turning off and on the circulation of fluid through the radiator.

In cold weather, especially at low engine loads, almost all the heat is removed as a result of cold air blowing over the engine, and coolant does not circulate through the radiator.

To maintain optimal engine temperature conditions at subzero ambient temperatures, it is necessary to cover the radiator trim with a cover.

Under no circumstances should you remove the thermostat.

In the cold season, an engine without a thermostat takes a long time to warm up and operates at a low coolant temperature.

As a result, its wear accelerates, fuel consumption increases, there is an abundant deposition of tarry substances in the engine, and normal air temperature in the car cabin is not ensured.

In the warm season, in the absence of a thermostat, most of the coolant will circulate in a small circle (through the engine cooling jacket), bypassing the radiator.

As a result, this will cause the engine to overheat.

Replacing the thermostat on the ZMZ-406 engine

Drain the liquid from the cooling system, article - "Replacing the engine coolant"

Replacing the thermostat on the ZMZ-406 engine

Disconnect the two hoses from the pipes of cover 1 of the thermostat housing.

Unscrew two bolts 2 and remove cover 1.

If you need to remove the thermostat housing, you need to disconnect the wires from the sensors 5, loosen the tightening of the clamps 4 and, after unscrewing the two bolts 3, remove the thermostat housing

Replacing the thermostat on the ZMZ-406 engine

Remove thermostat 1 from housing 2

Install the new thermostat in reverse order.

Replacing the thermostat on the ZMZ-402 engine

Drain the cooling system.

Replacing the thermostat on the ZMZ-402 engine

Disconnect hoses 1 and 2 from cover 6 of the thermostat housing, having first loosened the clamps.

If you need to remove the thermostat housing, you need to disconnect hose 3 from it and wire 4 from the coolant temperature sensor.

Unscrew two bolts 5 (the second bolt from the bottom of the housing) and remove the thermostat housing.

Replacing the thermostat on the ZMZ-402 engine

Unscrew the two bolts 1 and remove the cover 2. Remove the thermostat 3 from the housing

Install the new thermostat in reverse order.

new

The lubrication system diagram is shown in Fig. 1. Oil pressure in the lubrication system of a warm engine at low crankshaft speed 550–650 min -1

In the article we will consider possible malfunctions of the front axle of the UAZ-3151